using Microsoft.Extensions.Logging;
using SeataNet.Core.Saga;
using SeataNet.Core.TCC;
using SeataNet.Core.Transaction;

namespace SeataNet.Samples
{
    public class PaymentService
    {
        private readonly ITransactionManager _transactionManager;
        private readonly ILogger<PaymentService> _logger;

        public PaymentService(
            ITransactionManager transactionManager,
            ILogger<PaymentService> logger)
        {
            _transactionManager = transactionManager;
            _logger = logger;
        }

        /// <summary>
        /// AT模式处理支付
        /// </summary>
        [GlobalTransactional(Name = "payment-process-at", Timeout = 30000)]
        public async Task<string> ProcessPaymentAsync(string orderId, string userId, decimal amount)
        {
            _logger.LogInformation($"开始处理支付，订单ID: {orderId}, 用户ID: {userId}, 金额: {amount}");
            
            // 1. 验证用户账户
            var accountValid = await ValidateUserAccountAsync(userId);
            if (!accountValid)
            {
                throw new InvalidOperationException("用户账户无效");
            }

            // 2. 检查余额
            var hasBalance = await CheckBalanceAsync(userId, amount);
            if (!hasBalance)
            {
                throw new InvalidOperationException("账户余额不足");
            }

            // 3. 扣款
            await DeductBalanceAsync(userId, amount);

            // 4. 记录支付记录
            var paymentId = Guid.NewGuid().ToString("N");
            await RecordPaymentAsync(paymentId, orderId, userId, amount);

            _logger.LogInformation($"支付处理成功，支付ID: {paymentId}");
            return paymentId;
        }

        /// <summary>
        /// TCC模式处理支付
        /// </summary>
        [GlobalTransactional(Name = "payment-process-tcc", Timeout = 30000)]
        public async Task<string> ProcessPaymentWithTccAsync(string orderId, string userId, decimal amount)
        {
            _logger.LogInformation($"开始TCC模式处理支付，订单ID: {orderId}, 用户ID: {userId}, 金额: {amount}");
            
            // 1. TCC模式验证用户账户
            var accountValid = await TryValidateUserAccountAsync(userId);
            if (!accountValid)
            {
                throw new InvalidOperationException("用户账户无效或验证失败");
            }

            // 2. TCC模式检查余额
            var balanceReserved = await TryReserveBalanceAsync(userId, amount);
            if (!balanceReserved)
            {
                throw new InvalidOperationException("余额预留失败");
            }

            // 3. TCC模式记录支付
            var paymentId = Guid.NewGuid().ToString("N");
            var paymentReserved = await TryRecordPaymentAsync(paymentId, orderId, userId, amount);
            if (!paymentReserved)
            {
                throw new InvalidOperationException("支付记录预留失败");
            }

            _logger.LogInformation($"TCC模式支付处理成功，支付ID: {paymentId}");
            return paymentId;
        }

        /// <summary>
        /// Saga模式处理支付
        /// </summary>
        [GlobalTransactional(Name = "payment-process-saga", Timeout = 60000)]
        public async Task<string> ProcessPaymentWithSagaAsync(string orderId, string userId, decimal amount)
        {
            _logger.LogInformation($"开始Saga模式处理支付，订单ID: {orderId}, 用户ID: {userId}, 金额: {amount}");
            
            // 1. 验证用户账户
            var accountValid = await ValidateUserAccountAsync(userId);
            if (!accountValid)
            {
                throw new InvalidOperationException("用户账户无效");
            }

            // 2. 检查余额
            var hasBalance = await CheckBalanceAsync(userId, amount);
            if (!hasBalance)
            {
                throw new InvalidOperationException("账户余额不足");
            }

            // 3. 扣款
            await DeductBalanceAsync(userId, amount);

            // 4. 记录支付记录
            var paymentId = Guid.NewGuid().ToString("N");
            await RecordPaymentAsync(paymentId, orderId, userId, amount);

            _logger.LogInformation($"Saga模式支付处理成功，支付ID: {paymentId}");
            return paymentId;
        }

        /// <summary>
        /// XA模式处理支付
        /// </summary>
        [GlobalTransactional(Name = "payment-process-xa", Timeout = 30000)]
        public async Task<string> ProcessPaymentXaAsync(string orderId, string userId, decimal amount)
        {
            _logger.LogInformation($"开始XA模式处理支付，订单ID: {orderId}, 用户ID: {userId}, 金额: {amount}");
            
            // 1. 验证用户账户
            var accountValid = await ValidateUserAccountAsync(userId);
            if (!accountValid)
            {
                throw new InvalidOperationException("用户账户无效");
            }

            // 2. 检查余额
            var hasBalance = await CheckBalanceAsync(userId, amount);
            if (!hasBalance)
            {
                throw new InvalidOperationException("账户余额不足");
            }

            // 3. 扣款
            await DeductBalanceXaAsync(userId, amount);

            // 4. 记录支付记录
            var paymentId = Guid.NewGuid().ToString("N");
            await RecordPaymentXaAsync(paymentId, orderId, userId, amount);

            _logger.LogInformation($"XA模式支付处理成功，支付ID: {paymentId}");
            return paymentId;
        }

        // TCC模式的Try方法
        public async Task<bool> TryProcessPaymentAsync(string orderId, string userId, decimal amount)
        {
            _logger.LogInformation($"TCC Try: 预留支付，订单ID: {orderId}, 用户ID: {userId}, 金额: {amount}");
            
            // 1. 验证用户账户
            var accountValid = await TryValidateUserAccountAsync(userId);
            if (!accountValid)
            {
                return false;
            }

            // 2. 预留余额
            var balanceReserved = await TryReserveBalanceAsync(userId, amount);
            if (!balanceReserved)
            {
                return false;
            }

            // 3. 预留支付记录
            var paymentId = Guid.NewGuid().ToString("N");
            var paymentReserved = await TryRecordPaymentAsync(paymentId, orderId, userId, amount);
            if (!paymentReserved)
            {
                return false;
            }

            return true;
        }

        private async Task<bool> ValidateUserAccountAsync(string userId)
        {
            // 模拟验证用户账户
            _logger.LogInformation($"验证用户账户: {userId}");
            await Task.Delay(30); // 模拟数据库操作
            return true; // 假设总是有效
        }

        private async Task<bool> TryValidateUserAccountAsync(string userId)
        {
            // 模拟TCC模式的Try阶段验证用户账户
            _logger.LogInformation($"TCC Try: 验证用户账户: {userId}");
            await Task.Delay(30); // 模拟数据库操作
            return true; // 假设总是有效
        }

        private async Task<bool> CheckBalanceAsync(string userId, decimal amount)
        {
            // 模拟检查用户余额
            _logger.LogInformation($"检查用户余额: {userId}, 金额: {amount}");
            await Task.Delay(30); // 模拟数据库操作
            return true; // 假设余额充足
        }

        private async Task<bool> TryReserveBalanceAsync(string userId, decimal amount)
        {
            // 模拟TCC模式的Try阶段预留余额
            _logger.LogInformation($"TCC Try: 预留用户余额: {userId}, 金额: {amount}");
            await Task.Delay(30); // 模拟数据库操作
            return true; // 假设总是成功
        }

        private async Task DeductBalanceAsync(string userId, decimal amount)
        {
            // 模拟扣减用户余额
            _logger.LogInformation($"扣减用户余额: {userId}, 金额: {amount}");
            await Task.Delay(30); // 模拟数据库操作
        }

        private async Task DeductBalanceXaAsync(string userId, decimal amount)
        {
            // 模拟XA模式扣减用户余额
            _logger.LogInformation($"XA扣减用户余额: {userId}, 金额: {amount}");
            await Task.Delay(30); // 模拟数据库操作
        }

        private async Task RecordPaymentAsync(string paymentId, string orderId, string userId, decimal amount)
        {
            // 模拟记录支付记录
            _logger.LogInformation($"记录支付记录: {paymentId}, 订单ID: {orderId}, 用户ID: {userId}, 金额: {amount}");
            await Task.Delay(30); // 模拟数据库操作
        }

        private async Task<bool> TryRecordPaymentAsync(string paymentId, string orderId, string userId, decimal amount)
        {
            // 模拟TCC模式的Try阶段记录支付记录
            _logger.LogInformation($"TCC Try: 预留支付记录: {paymentId}, 订单ID: {orderId}, 用户ID: {userId}, 金额: {amount}");
            await Task.Delay(30); // 模拟数据库操作
            return true; // 假设总是成功
        }

        private async Task RecordPaymentXaAsync(string paymentId, string orderId, string userId, decimal amount)
        {
            // 模拟XA模式记录支付记录
            _logger.LogInformation($"XA记录支付记录: {paymentId}, 订单ID: {orderId}, 用户ID: {userId}, 金额: {amount}");
            await Task.Delay(30); // 模拟数据库操作
        }

        // TCC模式的Confirm方法
        [GlobalTransactionalConfirm]
        public async Task ConfirmPaymentAsync(string paymentId)
        {
            _logger.LogInformation($"TCC Confirm: 确认支付: {paymentId}");
            await Task.Delay(20); // 模拟数据库操作
        }

        // TCC模式的Cancel方法
        [GlobalTransactionalCancel]
        public async Task CancelPaymentAsync(string paymentId)
        {
            _logger.LogInformation($"TCC Cancel: 取消支付: {paymentId}");
            await Task.Delay(20); // 模拟数据库操作
        }

        // Saga模式的补偿方法
        [GlobalTransactionalCompensation]
        public async Task CompensatePaymentAsync(string paymentId, decimal amount)
        {
            _logger.LogInformation($"Saga Compensate: 补偿支付: {paymentId}, 金额: {amount}");
            await Task.Delay(20); // 模拟数据库操作
        }
    }
}